Search PubMed⌕ Search

Biomedical subjects

D U Kim

Publications and source records attributed to D U Kim.

At least 37 records · Page 2Linked to original sources

FGF-1 affixation stimulates ePTFE endothelialization without intimal hyperplasia.

The affixation of FGF-1 to porous vascular grafts has been reported to stimulate capillary ingrowth and surface endothelialization. The current study further characterizes responses to fibroblast growth factor (FGF)-1 affixation to 30-cm-long grafts followed 140 days. ePTFE grafts (30 cm x 8 mm i.d.), 60 microns internodal distance, were impregnated with fibrin glue (FG) suspensions containing FGF-1 and heparin. Two negative control groups were treated either with FG with heparin alone or left untreated. Grafts were explanted from the canine thoracoabdominal aortic position after 10, 30, or 140 days (n = 3/time/group) 10 hr after im injection of tritiated thymidine (0.5 muCi/kg). Specimens were studied by light and electron microscopy, immunohistochemistry, morphometric analyses, and cross-sectional autoradiography. RNA preparations from inner capsule tissues were used for reverse transcription-polymerase chain reaction (RT-PCR) analyses of FGF-1, FGF-2, transforming growth factor-beta 1, (TGF-beta 1) and FGF receptor mRNA species. Inner capsule collagen was quantitated by hydroxyproline colorimetry. Histologic analyses of perianastomotic regions were performed for comparison purposes. All explants were patent and without intimal hyperplasia. Progressive capillarization of the internodal spaces occurred over time and was significantly more extensive in the FGF-1-treated group. Endothelialization of the luminal surface increased with time, at 140 days covering 86.7 +/- 11.6% of the FGF-1 explants vs 46.1 +/- 7.5% and 48.1 +/- 13.3% in the other groups, P < 0.007 and P < 0.04, respectively. Inner capsule thickness at 140 days differed significantly (P < 0.05) between the FGF-1 group (138.8 microns) vs either control group (93 and 67 microns, respectively), which did not significantly differ from each other. Cross-sectional autoradiography demonstrated an FGF-1-induced mitotic index increase at 30 days, 9.6 +/- 4.4% compared to 2.5 +/- 1.0 and 0 +/- 0%, respectively, with both myofibroblasts and endothelial cells incorporating the [3H]thymidine label. The mitotic index returned to quiescent levels at 140 days (< 1% in all groups). Collagen content increased with time in all groups, significantly greater in both FG groups vs untreated controls at 30 and 140 days. RT-PCR analyses revealed FGF-1, FGF-2, FGFR-1 (flg), and TGF-beta 1 mRNA in all samples without evidence of modulation by FGF-1 affixation. These data demonstrate FGF-1-induced graft capillarization and surface endothelialization without functionally significant intimal hyperplasia in this model.

Animals↗

Kinetics of cell proliferation as a function of vascular graft material.

Bioresorbable vascular grafts constructed for polyglactin 910 (PG910) and polydioxanone (PDS) and nonresorbable Dacron were interposed into the infrarenal abdominal aortas of New Zealand White rabbits. The prosthesis/tissue complexes were harvested after 2, 3, 4, 12, and 52 weeks. Seventeen, 9, and 1 h prior to sacrifice, animals received tritiated thymidine (0.5 mCi/kg/dose). All specimens were studied grossly and by light and transmission electron microscopy. Mitotic indices (MI's) were determined by autoradiography for inner capsule myofibroblasts at the proximal, mid, and distal segments of each prosthesis. There were no aortic-related deaths. All grafts were patent with no aneurysmal dilatation. At 4 weeks, PG910 resorption was evidenced by macrophage phagocytosis, less so in PDS while Dacron remained intact. At 12 weeks, the PG910 was completely resorbed while PDS resorption continued. The latter was completely resorbed by 52 weeks. There was no significant difference in MI's between proximal, mid, and distal regions for each graft type. The mitotic index paralleled the rate of prosthetic resorption in both PG910 and PDS groups, as high as 28.34 +/- 23.21 in the former 3 weeks after implantation and significantly higher at 4 weeks (7.58 +/- 2.02 and 7.50 +/- 2.66, respectively) than at 52 weeks (0.72 +/- 0.98 and 1.00 +/- 0.22, respectively) in both groups. The mitotic index in the Dacron group never surpassed 1.22 +/- 0.90. We conclude that higher levels of early cell proliferation in bioresorbable grafts closely parallel the kinetics of prosthetic resorption.

Animals↗

Pure seminoma arising in androgen insensitivity syndrome (testicular feminization syndrome): a case report and review of the literature.

This is a case of a young woman who had testicular feminization syndrome and developed a seminoma in an undescended intrapelvic testis. Androgen insensitivity (testicular feminization) syndrome is a rare inherited form of male pseudohermaphroditism that occurs in phenotypically normal women with adequate breast development, normal external genitalia, a vagina of variable depth, absent uterus, and sparse or absent pubic and axillary hair. The gonad (undescended testes) may be intraabdominal, inguinal, or labial. These patients characteristically have male karyotype (XY) and negative sex chromatin and are at increased risk of undergoing malignant transformation of the undescended gonad. We review the literature emphasizing the biochemical and endocrinologic abnormalities leading to the syndrome, as well as the morphologic abnormalities (light microscopic) of the undescended testes, diagnosis, and therapeutic management.

Adult↗

Polypropylene small-diameter vascular grafts.

Polypropylene's physical properties (e.g., high tensile strength) and relatively inert behavior suggest that fabrication into an arterial substitute may result in an efficacious prosthesis. Grafts were woven from polypropylene yarn into conduits 4 mm I.D. x 50 mm in length. Control grafts were Dacron and ePTFE. Baseline platelet aggregometry on all dogs was performed with 10(-5) M ADP. Aspirin and dipyridamole were given for three days preoperatively and maintained for 2 weeks after surgery. Fifty-four grafts were placed into the aortoiliac position, two different graft materials per dog. The grafts were explanted at intervals of 2 weeks through 16 months; photographed for thrombus-free surface area determinations; and preserved for light, scanning, and transmission electron microscopy. Late (4-16 month) patency was 81% (13/16) for polypropylene, 69% (9/13) for Dacron, and 20% (1/5) for ePTFE. These data include one year patencies of 11/12 (92%) for polypropylene and 7/10 (70%) for Dacron. Late patency for polypropylene grafts was better than for PTFE (p less than 0.05). Platelet aggregation status did not predict graft patency. Light microscopy of 2-week polypropylene explants showed inner capsules composed of myofibroblasts and macrophages, with patchy areas of endothelial cells lining the lumen. By 1 month, a confluent endothelialized surface was seen in all polypropylene explants. Progressive thickening of inner capsules with myofibroblasts and collagen continued through 4 months, reaching a mean thickness of 142 +/- 50 microns (compared to 150 +/- 30 microns for Dacron). These findings suggest potential clinical efficacy for polypropylene as an arterial substitute.

Adenosine Diphosphate↗

Spatial and temporal changes in compliance following implantation of bioresorbable vascular grafts.

Compliance matching between the host vessel and vascular grafts used for small-diameter arterial replacements is thought to be important for long-term patency. However, currently available grafts elicit fibroplastic reactions, resulting in decreasing compliance with time after implantation. Bioresorbable prostheses elicit ingrowth of myofibroblasts containing abundant contractile elements. This led us to investigate whether compliance of implanted bioresorbable prostheses decreased as a function of time and if the kinetics of change correlated with the progression of tissue ingrowth. Woven polyglactin 910 prostheses (10 mm x 4 mm i.d.) were implanted into adult NZW rabbit infrarenal aortas and replicates were harvested serially through 8 months. Control grafts were implanted, and immediately resected. Dynamic compliance was measured at 1-mm axial increments along each explant using a pulse duplicator apparatus which exposed the harvested samples to realistic pulsatile hemodynamics. Compliance was calculated for proximal, mid, and distal segments of each graft and averaged at each time point by grouping into control (zero time, n = 3), early (1-4 weeks, n = 13), and late (6-36 weeks, n = 9) explant periods. At late explant periods both proximal and distal compliance were significantly greater than mid graft compliance (p < .02 and p < .03, respectively). There was a significant increase in proximal compliance between early and late explant times (p < .01). Measured increases in mid and distal segment compliance over time did not reach statistical significance. Myofibroblast laden tissue ingrowth into the inner capsule followed macrophage phagocytosis and was nearly complete prior to the time that an increase in compliance was demonstrated. Thus since the major histologic episodes precede the change in compliance, these are not likely initiated by this biomechanical change. We hypothesize the graft resorption coupled with the ingrowth of more compliant tissue likely leads to the increased compliance of the graft material.

Animals↗

Enhanced endothelialization of expanded polytetrafluoroethylene grafts by fibroblast growth factor type 1 pretreatment.

BACKGROUND: Biomaterial pretreatment with endothelial cell mitogens may enhance endothelialization. METHODS: Modified fibrin glue (FG) containing 1 ng/cm2 recombinant 125I-labeled fibroblast growth factor type 1 (125I-FGF-1), 20 micrograms/cm2 heparin, 2.86 mg/cm2 fibrinogen, and 2.86 x 10(-2) units/cm2 thrombin was pressure perfused into expanded polytetrafluoroethylene (ePTFE) grafts. Grafts were interposed into infrarenal aortas of 24 New Zealand white rabbits and explanted after 0, 5, 30, and 60 minutes and 1, 7, 14, and 30 days. Residual radioactivity was determined by gamma-counting. Remaining 125I-FGF-1 is expressed as percent of value at time 0. To determine the effect of the FG/FGF-1 on graft healing, three groups of 50 x 4 mm 60 microns internodal-distance nonreinforced ePTFE grafts were implanted in the aortoiliac position of 12 dogs. Group I (n = 12) contained the complete modified FG, group II (n = 6) contained FG with heparin but no FGF-1, and group III (n = 6) contained untreated identical ePTFE. Tritiated thymidine (0.5 microCi/kg) was injected intramuscularly 10 hours before explantation after 7 and 28 days for light and electron microscopy and en face autoradiography. RESULTS: Retention of 125I-FGF-1 showed rapid initial loss (delta %/delta min = -24.1) followed by slow loss after 1 hour (delta %/delta min = -0.03), with 13.4% +/- 6.9% remaining at 1 week and 3.8% +/- 1.1% at 30 days. Every FG/FGF-1 graft at 28 days showed extensive capillary ingrowth and confluent endothelialized luminal surfaces, not seen in any specimen of the other two groups. Autoradiography revealed a significant increase (p less than 0.05) in 3H-thymidine incorporation in the FG/FGF-1 grafts at 28 days versus all groups as a function of time and graft treatment. CONCLUSIONS: Pressure perfusion of an FGF-1/FG suspension into 60 microns internodal-distance ePTFE grafts promotes endothelialization through capillary ingrowth and increased endothelial cell proliferation.

Animals↗

The effects of an atherogenic diet on macrophage/biomaterial interactions.

We previously reported that biomaterials differentially induced macrophages to secrete growth factors that mediate reendothelialization. The present study evaluates the effect of an atherogenic diet on macrophage/biomaterial interactions. Female New Zealand white rabbits were fed an atherogenic diet. Peritoneal macrophages were harvested from these as well as rabbits fed a normal diet and cultured in Minimum Essential Medium with platelet-poor serum. Dacron or polyglactin 910 were added to two of three conditions of both cell groups in passage 2. Conditioned media were collected weekly through week 15. Mitogenicity assays were performed with quiescent mouse embryonal (BALB/c3T3) fibroblasts, atherosclerotic rabbit aortic smooth muscle cells, and murine capillary lung (LE-II) endothelial cells. Mitogenic activity was assayed by scintillation counting of tritiated thymidine incorporation into deoxyribonucleic acid (DNA). Results showed increased mitogenic activity released by macrophages from atherosclerotic rabbits, in the absence of prosthetic material, when assayed against every cell line. In normal diet macrophages, polyglactin 910 stimulated mitogen release for every cell line, and Dacron yielded minimal mitogen release. In lipid diet macrophages polyglactin 910 slightly increased mitogen release for all three cell lines, whereas Dacron resulted in stimulation of DNA synthesis in smooth muscle cells and BALB/c3T3 cells but less DNA synthesis in LE-II cells than in control, no graft material, media. Western blotting demonstrated immunoreactivity to basic fibroblast growth factor in media from normal diet macrophages but only in the presence of polyglactin 910 or Dacron. Radioimmunoassay for platelet-derived growth factor B chain was negative in all groups, and polymerase chain reaction techniques to amplify transforming growth factor-beta messenger ribonucleic was negative. These data demonstrate the effect of in vivo dietary manipulation on macrophage activation as well as the effect of an atherogenic diet in modulating macrophage/biomaterial interactions. Additionally, different biomaterials differentially induce macrophages to release factors that stimulate and inhibit growth.

Animals↗

Effects of hypercholesterolemia on healing of vascular grafts.

Small-diameter vascular grafts woven from bioresorbable lactide/glycolide copolymers have been successfully interposed into aortas of normal NZW rabbits. The current study examines the histologic and functional reactions to these bioresorbable grafts in severely hypercholesterolemic rabbits, a standard animal model of atherosclerosis. Sixty rabbits were placed on a 2% cholesterol, 6% peanut oil atherogenic diet. Baseline serum cholesterols and triglycerides were measured and repeated at operation 3 months later. Woven polyglactin 910 (PG910) grafts were interposed into infrarenal aortas. Fifty-two rabbits died on the diet or within 3 days of surgery and eight survived operation (normal NZW rabbit operative mortality is less than 10%). Cholesterol levels rose from 63 to 1989, p less than .001. Of the eight survivors, five died after 3 weeks, and one died after 2 1/2 months. Two were sacrificed at 2 and 4 months. Four aortic disruptions with retroperitoneal hematomas, one pseudoaneurysm, and one diffuse aneurysm were observed, greater than in normal rabbits, p less than .001. Inspection revealed severe atherosclerosis. Histologically, 3-week explants showed only small areas of neointima with myofibroblasts and endothelial cells; the outer capsules were infiltrated by lipid-laden macrophages. Graft material in 2- to 4-month explants was replaced by tissue with histologic atherosclerosis. More severe atherosclerosis was observed in native aortas at the perianastomotic areas than the more distant aortic segments. Abundant intracellular lipid was seen also in splenic histiocytes and hepatic cells with evidence of micronodular cirrhosis. Macrophages phagocytizing bioresorbable prostheses may release growth factors mediating the formation of a cellular tissue conduit. Severe hypercholesterolemia may alter monokine release from macrophages resulting in a weakened prosthesis/tissue complex.

Animals↗

Partially bioresorbable vascular grafts in dogs.

Previous studies have shown the effectiveness of partially resorbable arterial prostheses in the rabbit. This study compares these same compound prostheses with commercial graft materials in the dog. Conduits 4 mm inner diameter X 50 mm in length were woven from composite yarns containing 69% polyglactin 910 (PG910)/31% polypropylene or containing 70% polydioxanone/30% polypropylene. Nonresorbable controls were woven Dacron and expanded polytetrafluoroethylene (ePTFE). Baseline platelet aggregometry to 10(-5) mol/L adenosine diphosphate was performed. Seventy prostheses were implanted into the aorto-ilac positions, and the prosthesis/tissue complexes were harvested serially from 2 weeks to 1 year. Explanted specimens were photographed and fixed for light microscopy and for scanning and transmission electron microscopy. Results showed no aneurysms or perigraft hematomas. Overall patency for the PG910/polypropylene grafts was 18 of 20 (90%) and for polydioxanone/polypropylene was 19 of 22 (86%). For Dacron and ePTFE, 13 of 19 (68%) and 6 of 11 (54%) remained patent at time of explantation. The partially resorbable grafts, as a group, had significantly greater patency than the control grafts (p less than 0.03). Platelet aggregometry was not predictive of graft patency. Histologic analysis of the partially bioresorbable groups showed inner capsules (IC) composed of myofibroblasts and collagen beneath confluent endothelialized surfaces by 1 month. Kinetics of IC formation paralleled the rates of resorption of the resorbable components. IC cellularity and thickness were greater than those within Dacron or ePTFE. This study suggests an enhanced transinterstitial endothelial cell and myofibroblast ingrowth into the ICs of partially resorbable grafts and shows the effectiveness of these prostheses in the dog.

Absorption↗

The effects of shear stress on endothelial cell retention and function on expanded polytetrafluoroethylene.

We evaluated the adherence of indium 111-radiolabeled endothelial cells to fibronectin-treated expanded polytetrafluoroethylene surfaces exposed to high (437 s-1) vs low (218 s-1) shear and the influence of shear on prostacyclin production. Canine jugular vein factor VIII-positive endothelial cells in passages 3 through 6 were incubated with 111Indium-oxine, and labeled cells were seeded onto fibronectin-treated expanded polytetrafluoroethylene patches. Patches with confluent cells were exposed to shear in a Weissenberg rheogoniometer for intervals ranging up to 60 minutes. Percent endothelial cell retention was determined by gamma counting of patches and media and by histologic evaluation. Prostacyclin production (tritiated radioimmunoassay of 6-keto-prostaglandin F1 alpha) was assayed on perfusing media. Results showed no differences in 6-keto-prostaglandin F1 alpha production between shear rates or time periods. Endothelial cell retention did not differ between the shear rates. Rotational shear caused persistent cell loss over time in either high- or low-shear conditions. This persistent cell loss in response to steady rotational shear differs from that in response to identical rates of pulsatile linear shear in our laboratory where cell loss approached zero after 15 minutes.

Animals↗

Effects of class I heparin binding growth factor and fibronectin on platelet adhesion and aggregation.

Fibronectin and heparin binding growth factor-type 1 have been affixed to vascular graft surfaces to enhance the attachment and the proliferation of transplanted endothelial cells, respectively. The current study examines the effect of fibronectin and heparin binding growth factor-type 1 on platelet adhesion and activation in vivo and on platelet aggregation in vitro. Expanded polytetrafluoroethylene prostheses (5 cm x 4 mm internal diameter) were treated either with fibronectin (n = 9), fibronectin/heparin/heparin binding growth factor-type 1/heparin (n = 12), or neither (n = 13) and were interposed into canine aortoiliac systems bilaterally. Autogenous radiolabeled (Indium 111 oxine, 650 microCi) platelets were injected intravenously before reestablishment of circulation. Perfusion was maintained for 30 minutes, and prostheses were removed with segments of native aorta and distal iliac arteries bilaterally. Specimens were examined for thrombus-free surface area, by gamma well counting for adherent radiolabeled platelets, and by light microscopy and transmission and scanning electron microscopic techniques. Results showed that both the fibronectin and fibronectin/heparin/heparin binding growth factor-type 1/heparin pretreated prostheses contained significantly greater numbers of platelets and adherent radioactivity than did control graft segments when normalized to their ipsilateral iliac arteries. Fibronectin/heparin/heparin binding growth factor-type 1/heparin pretreated prostheses contained 27 +/- 16 times more radioactivity per square millimeter than ipsilateral iliac arteries, fibronectin pretreated prostheses had 13 +/- 8 times more radioactivity per square millimeter than ipsilateral iliac arteries, and untreated expanded polytetrafluoroethylene had 4 +/- 3 times more radioactivity per square millimeter than ipsilateral iliac arteries. Fibronectin/heparin/heparin binding growth factor-type 1/heparin was more radioactive than fibronectin alone (p = 0.056). Histologic evaluation and thrombus-free surface area determinations corroborated the gamma well counting data. Platelet aggregation in vitro was not activated by either fibronectin (1 to 100 micrograms/100 microliters) or heparin binding growth factor-type 1 (25 to 2500 ng/100 microliters). These data suggest that fibronectin and heparin binding growth factor-type 1 promote platelet adhesion not aggregation.

Animals↗

Hepatitis-B-associated glomerulonephritis: pathology, pathogenesis, and clinical course.

Hepatitis-B-associated glomerulonephritis (HBGN) is a distinct entity occurring frequently in hepatitis-B-prevalent areas of the world. The disease affects both adults and children who are chronic hepatitis-B-virus (HBV) carriers with or without a history of overt liver disease. The diagnosis is established by serologic evidence of HBV antigens/antibodies, presence of an immune complex glomerulonephritis, immunohistochemical localization of 1 or more HBV antigens, and pertinent clinical history, when available. In this study we present clinicopathologic and follow-up findings in 12 patients (7 children, 5 adults) with hepatitis-B-associated glomerulonephritis. Twelve patients provided 15 renal biopsies and 1 specimen of kidney tissue, obtained at autopsy; these were examined by light microscopy, electron microscopy, and immunohistochemical methods. Membranous glomerulonephritis (MGN) with or without mesangial proliferation was noted in 7 biopsies, mesangiocapillary (membranoproliferative) glomerulonephritis (MCGN) in 5 biopsies, and proliferative glomerulonephritis with or without membranous changes in 2 biopsies. Tubulointerstitial changes were minimal except in 3 adults, in whom they were attributable to arterionephrosclerosis. Ultrastructural findings included the presence of considerable amounts of focal or diffuse granular electron-dense deposits in the glomeruli, in the subepithelial, subendothelial, and mesangial locations, occasionally destroying or replacing the lamina densa of the basement membrane. Variable mesangial proliferation was also observed, with interposition, with focal irregular reduplication of the basement membranes and rare clusters of spherical particles, probably representing viral particles in the deposits. In addition, granular deposits along tubular basement membranes were seen in 1 case. The glomerular deposits stained for 2 or more immunoglobulins, the predominant one being IgG, and variably also for complement components (C3, C4 and C1q). Hepatitis B viral antigens (HBsAg, HBcAg, HBeAg) were demonstrated using acid elution techniques in the deposits in all biopsies where frozen tissue was available, singly or in a variety of combinations and intensities. There were deposits of IgG, C3, C1q, and HBsAg along the tubular basement membranes in 1 case. Follow-up biopsies in 2 cases, 2 and 5 years apart, showed a transformation from a diffuse MGN to MCGN with segmental membranous features. Follow-up biopsy after 3 years in the third patient, who went into clinical remission, revealed partially resolving glomerular lesions. Renal lesions secondary to chronic liver disease, parasitic diseases, certain tropical nephropathies, and lupus nephritis are some of the diseases that may morphologically resemble HBGN. Recognition and differentiation of HBGN from other entities may have significant prognostic and therapeutic implications.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗

Morphometric analysis of glomerular basement membranes (GBM) in thin basement membrane disease (TBMD).

We measured the thickness of glomerular basement membrane in 46 patients with thin basement membrane disease (TBMD), (age range 15-50 years, almost equal M:F ratio), and compared with that in a control group of 5 patients (age range 5-38 years) with normal glomerular morphology. The measurements of glomerular basement membrane taken from electron micrographs (magnification x 12,500) were analyzed using an interactive image analysis system assembled around an INTEL 10 microcomputer, with a high resolution touch sensitive screen as the interactive peripheral. Calculation was done by printing on an electron micrograph a grating replica (21,600 lines/cm), with the same magnification as the electron micrographs of the glomeruli and calibrating the arithmetic (AM) and harmonic (HM) mean for each case. Comparing the results of TBMD cases (AM 129-202 nm; HM 128-213 nm) with those of the control group consisting of 5 cases of "minimal change nephrotic syndrome" (AM 287-317 nm; HM 300-333 nm) it was found that GBM in TBMD is remarkably thin. The thinning was caused mainly by the decreased width of the lamina densa (TBMD group: 71.4-147.0 nm; HM 72.4-154.4 nm in comparison with the control group: AM 174.4-235.5 nm; HM 184.2-249.6 nm). This finding allows us to differentiate thin basement membrane disease from other glomerulopathies presenting primarily with isolated or recurrent hematuria.

Adolescent↗

Plasma polymerized tetrafluoroethylene/polyethylene terephthalate vascular prostheses.

Tetrafluoroethylene (TFE) was discharged onto woven polyethylene terephthalate (PET) prostheses, and the PET prostheses (50 mm long) with or without TFE were implanted into canine carotid arteries and aortas. Additional controls included polytetrafluoroethylene and Dacron. Specimens were explanted after one to 12 months, photographed, and sectioned for light and scanning and transmission electron microscopy, and thrombus-free surface areas calculated by computerized planimetry. Results showed no significant patency differences among carotid or aortic groups. However, both PET carotid groups had significantly greater thrombus-free surface areas. Histologically, both PET groups appeared identical. An endothelialized neointima covered PET carotid specimens by six months, compared with three months in the aortic position, with greater pannus ingrowth in both PET groups. Plasma polymerized TFE offered no additional advantage in these long-term experiments.

Animals↗

Blood component transfusion audit: a comprehensive microcomputer program.

Blood usage review is an essential aspect of hospital quality assurance. As part of a system for reviewing transfusion practices, the American Red Cross/New Jersey Blood Services has developed a series of microcomputer programs called the Blood Component Transfusion Audit. The programs use transfusion data collected on a standardized form to produce reports of utilization and analyses of transfusion practices, including the extent to which transfusions are justified by established criteria.

Blood Transfusion↗

Regional blood usage review: a quality assessment study from New Jersey hospitals.

In 1986, the American Red Cross/New Jersey Blood Service (NJBS) conducted a blood utilization review of the use of red blood cells (RBCs), platelets, and fresh frozen plasma (FFP) in nine hospitals in the NJBS region. The director of NJBS analyzed the collected data and categorized the justification criteria for blood transfusion. Their study found that female patients and patients over 60 years of age are the largest users of blood products, the average number of RBC units used is three, and the most common indication for RBC use is hypovolemia due to surgery. There was a high degree of compliance with justified criteria of use for RBC transfusion, although platelet and FFP use and pretransfusion nursing documentation require improvement.

Blood Transfusion↗

Vascular grafting in the management of thrombotic disorders.

Currently available vascular prostheses yield lower patency rates than do autogenous vascular grafts when implanted into small and medium caliber arteries, in part due to the relatively thrombogenic nature of the tissue reactions that they elicit. Our laboratory has developed techniques for enhancing spontaneous reendothelialization of blood-contacting biomaterials. Prostheses are constructed of bioresorbable lactide-glycolide copolymers that are phagocytized by macrophages. After implantation into animal models, they elicit extensive transinterstitial capillary infiltration and an early endothelialized luminal surface that responds to sodium arachidonate by production of 6-keto-PGF1 alpha at rates resembling normal control artery. Concurrent cell culture studies have shown that macrophages in culture with these copolymers release into their media growth factors mitogenic for quiescent endothelial cells. Additional studies have developed a method of affixing (ECGF) to biomaterial surfaces. The future development of more clinically efficacious small vessel prostheses will depend on optimization of the tissue reactions, including either enhancement of spontaneous endothelialization, endothelial cell transplantation, or prostheses pre-endothelialized in culture, and on the function of these endothelialized surfaces in an anticoagulant fashion.

Blood Vessel Prosthesis↗